Interchangeable electric switch heaters



Sept- 22, 1964 F. w. HOLSTEIN 3,150,252

INTERCHANGEABLE ELECTRIC swnca HEATERS Filed May 23. 1962 I I I II ,"J 3

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FIG-5 INVENTOR. Yup W HOLSTEIN Fl BY United States Patent Office li atented Sept. 22, 1964 3,150,252 INTERCHANGEABLE ELEtITRIC SWETCH HEATERS Fred W. Holstein, Hopatcong, N.J., assignor to The Rails Company, Maplewood, NJ. Filed May 23, 1962, Ser. No. 196,959 3 Claims. (Cl.'219--535) My invention relates to interchangeable electric switch heaters for railroad switches to'melt snow and ice and permit free movement of the switch point at all times in all weathers;

Switch heaters are usually limited in size and voltage, if any attempt is made to concentrate the heat by an enclosure. My invention is unrestricted in this regard and can be used with 600 volt application and several thousand watts capacity. Complete self-contained interchangeable units may range in size from 15" in length to 40 or more and are self-clamped against the rail web by means and methods set forth hereafter, without drilling multiple holes in the rail web.

Wiring may be adapted to load conditions, placing a number of heaters in series or parallel, with full output for heavy snow in dead winter and less output under less severe conditions, and by the use of timing motors, selection of connections and periods of operation are readily made. Moreover, heaters of diiferent sizes may be readily interchanged at any time, as each is a complete, readily movable unit.

Novel features of my invention also include a preformed, exposed, elongated, looped armored heating element supported by a hollow, threaded stud which passes through the rail web and is bolted thereto, with a suitable junction box on the other side of the rail held by the same stud. Resilient clamping members may extend from the stud with ends overlying the looped portions of the heating element to hold same against the rail web without drilling the rail. If desired, magnetic blocks may be used to stiffen the clamping members or may themselves clamp the heating element to the rail.

With the foregoing and other objects in view, as will be apparent to those skilled in the art as the description proceeds, my invention resides in the details of construction described in the specification and particularly pointed out in the appended claims, it being understood that changes in the particular embodiment of my invention may be made within the scope of what is claimed withoutv departing from the spirit of the invention. I intend no limitation other than those of the claims when fairly interpreted in the light of the fulldisclosure and the present state of the art. Referring now to the accompanying drawing which is furnished solely for illustrative purposes,

FIG. 1 is a face view of a heating unit; FIG. 2 illustrates an alternate form; FIG. 3 shows a stud in section; FIG. 4 is an alternate form of clamping member; FIG. 5 illustrates a magnetic block configuration. Similar ref? erence characters relate to similar parts in all the views;

A hollow, threaded stud 1 has an open cup .or recessed head with side openings 2 to hold resilientq'clamping members 3 and similar openings 4 to receive the support ends 5 of the preformed, elongated, armored heating element 6, which may be looped to both sides of the stud 1"(FIG. 1) or to one side only (FIG. 2).

The flexible leads 7 from the heating element extend through the support portions 5 and pass through the hollow stud 1 to any junction box on the other side of the rail. Such box (not shown) may be clamped to the rail by the same nut that fastens the stud, as shown, for example, in my Patent 2,910,567 of October 27, 1959. The cupped head of the stud 1 may be covered but I prefer to fill it with epoxy resin to prevent moisture entering.

Clamping members 3 are resilient and formed at the ends to overlay the loops of the armored heater 6, spring action forcing the loops close to the rail. This action may be stiffened, if desired, by magnetic blocks 9, formed as in FIG. 5, and positioned, as indicated by dotted outlines, over members 3 and adhering to the steel rail web. Such blocks may be placed directly over the heating element 6, if desired.

Alternately the clamping member may be a resilient steel strip 3a (FIG. 4) with formed ends to overlay a heating element and an opening 10 through which the stud passes and clamps the strip under the head against a rail, the member 3a flexing outward over the element ti l 6, as in FIG. 2, to give desired pressure. It will be apparent that the unit of FIG. 2 may be duplicated on the other side of the stud, the two heating elements being connected in series or parallel, as desired.

What I claim is: i I. A switch heater unit comprising a preformed, looped, armored heating element adapted to lie flat against the web of a rail, a threaded hollow stud having a shallow head, said looped heating element having end portions terminating in and supported by the head of said stud, and an elongated, flexible resilient clamping member for said element extending from and supported by staid stud, having an outer free end overlying a looped portion of said heating element, whereby to resiliently clamp same to a rail web when said heater is positioned. 2. A self-contained switch heater unit comprising a hollow threaded stud, a looped, elongated, armored heating unit having supporting end portions terminating in the head of said stud and separate flexible resilient clamping means held by and extending out from said stud and having an outer free end overlying a loop of said heating element to resiliently clamp same to a rail web when said heater is positioned.

3. A self-contained interchangeable switch heater unit comprising a hollow threaded supporting stud,

a preformed heating unit comprising a looped armored heating element supported by said stud,

and independent resilient clamping means supported by said stud adapted to press said heating unit against the rail web on either side of said stud.

References Cited in the file of this patent UNITED STATES PATENTS 1,959,107 Packer May 15, 1934 2,523,876 .Nordstrom Sept. 26, 1950 2,749,753 Adams June 12, 1956 2,802,346 Simmons Aug. 13, 1957 2,910,567 Holstein Oct. 27, 1959 

2. A SELF-CONTAINED SWITCH HEATER UNIT COMPRISING A HOLLOW THREADED STUD, A LOOPED, ELONGATED, ARMORED HEATING UNIT HAVING SUPPORTING END PORTIONS TERMINATING IN THE HEAD OF SAID STUD AND SEPARATE FLEXIBLE RESILIENT CLAMPING MEANS HELD BY AND EXTENDING OUT FROM SAID STUD AND HAVING AN OUTER FREE END OVERLYING A LOOP OF SAID HEATING ELEMENT TO RESILIENTLY CLAMP SAME TO A RAIL WEB WHEN SAID HEATER IS POSITIONED. 